1 files changed, 348 insertions, 0 deletions
diff --git a/scripts/dtc/fdtput.c b/scripts/dtc/fdtput.c
new file mode 100644
index 000000000..a363c3cab
--- /dev/null
+++ b/scripts/dtc/fdtput.c
@@ -0,0 +1,348 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+ */
+
+#include <assert.h>
+#include <ctype.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <libfdt.h>
+
+#include "util.h"
+
+/* These are the operations we support */
+enum oper_type {
+	OPER_WRITE_PROP,		/* Write a property in a node */
+	OPER_CREATE_NODE,		/* Create a new node */
+};
+
+struct display_info {
+	enum oper_type oper;	/* operation to perform */
+	int type;		/* data type (s/i/u/x or 0 for default) */
+	int size;		/* data size (1/2/4) */
+	int verbose;		/* verbose output */
+	int auto_path;		/* automatically create all path components */
+};
+
+
+/**
+ * Report an error with a particular node.
+ *
+ * @param name		Node name to report error on
+ * @param namelen	Length of node name, or -1 to use entire string
+ * @param err		Error number to report (-FDT_ERR_...)
+ */
+static void report_error(const char *name, int namelen, int err)
+{
+	if (namelen == -1)
+		namelen = strlen(name);
+	fprintf(stderr, "Error at '%1.*s': %s\n", namelen, name,
+		fdt_strerror(err));
+}
+
+/**
+ * Encode a series of arguments in a property value.
+ *
+ * @param disp		Display information / options
+ * @param arg		List of arguments from command line
+ * @param arg_count	Number of arguments (may be 0)
+ * @param valuep	Returns buffer containing value
+ * @param *value_len	Returns length of value encoded
+ */
+static int encode_value(struct display_info *disp, char **arg, int arg_count,
+			char **valuep, int *value_len)
+{
+	char *value = NULL;	/* holding area for value */
+	int value_size = 0;	/* size of holding area */
+	char *ptr;		/* pointer to current value position */
+	int len;		/* length of this cell/string/byte */
+	int ival;
+	int upto;	/* the number of bytes we have written to buf */
+	char fmt[3];
+
+	upto = 0;
+
+	if (disp->verbose)
+		fprintf(stderr, "Decoding value:\n");
+
+	fmt[0] = '%';
+	fmt[1] = disp->type ? disp->type : 'd';
+	fmt[2] = '\0';
+	for (; arg_count > 0; arg++, arg_count--, upto += len) {
+		/* assume integer unless told otherwise */
+		if (disp->type == 's')
+			len = strlen(*arg) + 1;
+		else
+			len = disp->size == -1 ? 4 : disp->size;
+
+		/* enlarge our value buffer by a suitable margin if needed */
+		if (upto + len > value_size) {
+			value_size = (upto + len) + 500;
+			value = realloc(value, value_size);
+			if (!value) {
+				fprintf(stderr, "Out of mmory: cannot alloc "
+					"%d bytes\n", value_size);
+				return -1;
+			}
+		}
+
+		ptr = value + upto;
+		if (disp->type == 's') {
+			memcpy(ptr, *arg, len);
+			if (disp->verbose)
+				fprintf(stderr, "\tstring: '%s'\n", ptr);
+		} else {
+			int *iptr = (int *)ptr;
+			sscanf(*arg, fmt, &ival);
+			if (len == 4)
+				*iptr = cpu_to_fdt32(ival);
+			else
+				*ptr = (uint8_t)ival;
+			if (disp->verbose) {
+				fprintf(stderr, "\t%s: %d\n",
+					disp->size == 1 ? "byte" :
+					disp->size == 2 ? "short" : "int",
+					ival);
+			}
+		}
+	}
+	*value_len = upto;
+	*valuep = value;
+	if (disp->verbose)
+		fprintf(stderr, "Value size %d\n", upto);
+	return 0;
+}
+
+static int store_key_value(void *blob, const char *node_name,
+		const char *property, const char *buf, int len)
+{
+	int node;
+	int err;
+
+	node = fdt_path_offset(blob, node_name);
+	if (node < 0) {
+		report_error(node_name, -1, node);
+		return -1;
+	}
+
+	err = fdt_setprop(blob, node, property, buf, len);
+	if (err) {
+		report_error(property, -1, err);
+		return -1;
+	}
+	return 0;
+}
+
+/**
+ * Create paths as needed for all components of a path
+ *
+ * Any components of the path that do not exist are created. Errors are
+ * reported.
+ *
+ * @param blob		FDT blob to write into
+ * @param in_path	Path to process
+ * @return 0 if ok, -1 on error
+ */
+static int create_paths(void *blob, const char *in_path)
+{
+	const char *path = in_path;
+	const char *sep;
+	int node, offset = 0;
+
+	/* skip leading '/' */
+	while (*path == '/')
+		path++;
+
+	for (sep = path; *sep; path = sep + 1, offset = node) {
+		/* equivalent to strchrnul(), but it requires _GNU_SOURCE */
+		sep = strchr(path, '/');
+		if (!sep)
+			sep = path + strlen(path);
+
+		node = fdt_subnode_offset_namelen(blob, offset, path,
+				sep - path);
+		if (node == -FDT_ERR_NOTFOUND) {
+			node = fdt_add_subnode_namelen(blob, offset, path,
+						       sep - path);
+		}
+		if (node < 0) {
+			report_error(path, sep - path, node);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * Create a new node in the fdt.
+ *
+ * This will overwrite the node_name string. Any error is reported.
+ *
+ * TODO: Perhaps create fdt_path_offset_namelen() so we don't need to do this.
+ *
+ * @param blob		FDT blob to write into
+ * @param node_name	Name of node to create
+ * @return new node offset if found, or -1 on failure
+ */
+static int create_node(void *blob, const char *node_name)
+{
+	int node = 0;
+	char *p;
+
+	p = strrchr(node_name, '/');
+	if (!p) {
+		report_error(node_name, -1, -FDT_ERR_BADPATH);
+		return -1;
+	}
+	*p = '\0';
+
+	if (p > node_name) {
+		node = fdt_path_offset(blob, node_name);
+		if (node < 0) {
+			report_error(node_name, -1, node);
+			return -1;
+		}
+	}
+
+	node = fdt_add_subnode(blob, node, p + 1);
+	if (node < 0) {
+		report_error(p + 1, -1, node);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int do_fdtput(struct display_info *disp, const char *filename,
+		    char **arg, int arg_count)
+{
+	char *value;
+	char *blob;
+	int len, ret = 0;
+
+	blob = utilfdt_read(filename);
+	if (!blob)
+		return -1;
+
+	switch (disp->oper) {
+	case OPER_WRITE_PROP:
+		/*
+		 * Convert the arguments into a single binary value, then
+		 * store them into the property.
+		 */
+		assert(arg_count >= 2);
+		if (disp->auto_path && create_paths(blob, *arg))
+			return -1;
+		if (encode_value(disp, arg + 2, arg_count - 2, &value, &len) ||
+			store_key_value(blob, *arg, arg[1], value, len))
+			ret = -1;
+		break;
+	case OPER_CREATE_NODE:
+		for (; ret >= 0 && arg_count--; arg++) {
+			if (disp->auto_path)
+				ret = create_paths(blob, *arg);
+			else
+				ret = create_node(blob, *arg);
+		}
+		break;
+	}
+	if (ret >= 0)
+		ret = utilfdt_write(filename, blob);
+
+	free(blob);
+	return ret;
+}
+
+static const char *usage_msg =
+	"fdtput - write a property value to a device tree\n"
+	"\n"
+	"The command line arguments are joined together into a single value.\n"
+	"\n"
+	"Usage:\n"
+	"	fdtput <options> <dt file> <node> <property> [<value>...]\n"
+	"	fdtput -c <options> <dt file> [<node>...]\n"
+	"Options:\n"
+	"\t-c\t\tCreate nodes if they don't already exist\n"
+	"\t-p\t\tAutomatically create nodes as needed for the node path\n"
+	"\t-t <type>\tType of data\n"
+	"\t-v\t\tVerbose: display each value decoded from command line\n"
+	"\t-h\t\tPrint this help\n\n"
+	USAGE_TYPE_MSG;
+
+static void usage(const char *msg)
+{
+	if (msg)
+		fprintf(stderr, "Error: %s\n\n", msg);
+
+	fprintf(stderr, "%s", usage_msg);
+	exit(2);
+}
+
+int main(int argc, char *argv[])
+{
+	struct display_info disp;
+	char *filename = NULL;
+
+	memset(&disp, '\0', sizeof(disp));
+	disp.size = -1;
+	disp.oper = OPER_WRITE_PROP;
+	for (;;) {
+		int c = getopt(argc, argv, "chpt:v");
+		if (c == -1)
+			break;
+
+		/*
+		 * TODO: add options to:
+		 * - delete property
+		 * - delete node (optionally recursively)
+		 * - rename node
+		 * - pack fdt before writing
+		 * - set amount of free space when writing
+		 * - expand fdt if value doesn't fit
+		 */
+		switch (c) {
+		case 'c':
+			disp.oper = OPER_CREATE_NODE;
+			break;
+		case 'h':
+		case '?':
+			usage(NULL);
+		case 'p':
+			disp.auto_path = 1;
+			break;
+		case 't':
+			if (utilfdt_decode_type(optarg, &disp.type,
+					&disp.size))
+				usage("Invalid type string");
+			break;
+
+		case 'v':
+			disp.verbose = 1;
+			break;
+		}
+	}
+
+	if (optind < argc)
+		filename = argv[optind++];
+	if (!filename)
+		usage("Missing filename");
+
+	argv += optind;
+	argc -= optind;
+
+	if (disp.oper == OPER_WRITE_PROP) {
+		if (argc < 1)
+			usage("Missing node");
+		if (argc < 2)
+			usage("Missing property");
+	}
+
+	if (do_fdtput(&disp, filename, argv, argc))
+		return 1;
+	return 0;
+}